Carmack is cast as Will, a new neighbor who grows close to Scarlett (Clare Bowen).

Nashville - which also stars Connie Britton and Hayden Panettiere - continues on Wednesdays at 10/9c on ABC and airs on Thursdays at 10pm on More4 in the UK.

New cast addition Carmack is best known for playing spoilt teen Luke on The OC - since departing the teen drama in 2004, he has appeared in episodes of Desperate Housewives, NCIS and the 2011 film Shark Night 3D.